(a) Field of the Invention
The invention is related to a door lock of key-driven transmission structure, especially to a door lock structure which has the advantages of labor saving and convenience in key-rotation operation.
(b) Description of the Prior Art
A single-lock design is usually used in the conventional door lock, i.e. a single key is matched with a single lock for lock opening and closing. The most commonly used locks such as the cylinder locks, because of their singular structure, the lock can be easily pried out by a burglar with a tool to open the door and endanger the safety of residence.
There is another kind of lock which is constituted by a lock-bolt mechanism and a lock-tongue mechanism, whereof the lock-bolt mechanism is directly operated by a key for door lock closing and opening, while the lock-tongue mechanism has an outward extending lock-tongue structure as in a cylinder lock, whereof the said lock-tongue mechanism can be operated by pressing and rotation and allow the door to be temporarily closed by only combined the lock-tongue structure and the lock-hole of the door frame when the said lock-bolt mechanism is not yet locked.
Nonetheless, the lock with the above said lock-bolt mechanism and lock-tongue mechanism is not adequate enough to provide perfect household safety, since the lock-tongue mechanism only provides a temporary locking function while the actual door locking is still relied on the lock-bolt mechanism to provide. Therefore, it is the same as the simple single lock described above, if the lock-bolt mechanism is damaged by a burglar, its lock closing function will be lost to maintain the burglarproof function and that is a thing to be worried about.
There are other people propose that the lock-bolt mechanism can be combined with other auxiliary locks to enhance the burglarproof effect. However, due to the poor design of the other auxiliary locks, it is more labor demanding or the locking action cannot be reached at the same time with the auxiliary locks, such as that there are numerous inconveniences regarding this, so there are plenty of rooms for modifications.